Some seem quite bright, you could set the shutter speed to make them dark (and they'd be less blurred), that way they'd have better contrast and the rider would stand out more.
Looks like you may need to improve your panning, you'll get it with practice, on the more side on shorts.
With that camera it is possible pre-focus the camera on a spot where the rider will enter, that might help you.
I think 2 is the best, 3 would be better if it weren't back focused (hence where pre-focusing might come in handy).
yeah practice makes perfect i supose!
good to see some on my new track

i thought the colours seemed quite washed out, but im not a photgrapher so dont know how youd go about improving this...?!?!
Buy a dSLR because im not using one!

Yeah im liking the new track

Rich